Assuming the order of your iceberg is that the best stuff floats to the top, I would personally have this order:

Mainstream Content
Unpopular Content
==========
Inactive Users
Low-Effort Content
Trolls
Spam/Bots

I don't think that unpopular content is necessarily dead weight. It's like you said, just people without support networks or content that hasn't gotten traction. While the platform as a whole has growing pains, so do individual users. Once they give up and move to low-effort content or become inactive, that to me is when they become a burden on the platform (though inactive users have minimal burden on the blockchain, so even that's not all that bad).